Improvement in saw-sets



n. r. 600K.

Saw-Sets.

No. 145,724. Patented Dec.23,1s?3.

UNITED STATES PATENT OFFICE.

ROSWELL F. COOK, OF WEST POTSDAM, NEW YORK.

IMPROVEMENT IN SAW-SETS.

Specification formingpart of Letters Patent No.145,724, dated December23,1873; application tiled October 9, 1873.

A represents the frame or holder, whichv may be attached to the bench,or may be so constructed as to be held in the hand. In the rea-r lowerportion of the holder is a recess, b, in the lower side of which is aseries of notches, c. In the rear upper portion of the holder lugs Z areformed, and between these lugs the hammer E'and lever G are pivoted. Inthe heel of the hammer is a notch, j', which enga-ges with one end ofthe spring H, the

* other end of which engages with one of the series of notches cin therecess b. The spring H consists ot' a iiat strip of metal, bent midwayof its length, so as to form a resemblance to the letter V with itspoint rounded, and having its ends bent outward for engagement with thenotches.

It will be seen that when the spring is thus attached to the parts, asthe hammer rises the rear or central bent portion of the spring risestoward the hammer; and, as the hammer falls the spring falls in anopposite direction, thus oscillating in an are of a circle, of which thelower end of the sprin g' forms the center.

By moving the lower end of the spring farther into the recess, the forceof the hammer is increased, and by moving it farther out the force isdiminished, as the distance traveled and the consequent power exerted bythe spring depends upon the position of its lower end, which forms fthecenter of oscillation. Thus the force of the blow of the hamsprin g isreadily removed and replaced, springs of different degrees of tensionmay be used when desired, and a new spring may be inserted in place of abroken one without the use of tools, and without loss of time.

The lever G has its fulcrum on the same pivot with the hammer, andengages with the hammer at a point between the fulcrum and the long armby means of a pin or stud, 7c, working between two shoulders orprojections, l l, on the upper portion of the heel of the hammer.

By this arrangement the manipulation of the lever is facilitated, as thelever is in nearly an upright position, and consequently vmore out ofthe way ofthe hammer than when in a nearly horizontal position, theparts are more easily inserted in place, and more power is aequired thanif the point of engagement were beyond or below the fulcrum. By theoscillation of the spring on the lower end as a center, the upper end,or the end which operates the hammer, travels a distance three times asgreat, and thus acquires more power than a spring which has one endiixed; and, by having the spring so arranged as to rise toward thehammer as the hammer rises, it forms a bearing for the heel of thehammer and holds it in a raised position. When the lever is moved backit raises the hammer until it passes the dead point, when the hammersprings farther back, so that its heel comes in contact with the flatportion of the spring, an d is held in a raised position. A slightforward movement of the lever starts the hammer downward again until itpasses the deadpoint, when the spring completes the downstroke with asudden blow.

I claim as new and desire to secure by Let` ters Patent- Thecombination, substantially as described, in a saw-set, of a notchedframe and lever with a hammer having' an oscillating spring for operating the same.

